The decomposition of , to and on heating is an example of
Intermolecular redox change
Intramolecular redox change
Disproportionation or auto redox change
None of the above
The decomposition of , to and on heating is an example of
Intermolecular redox change
Intramolecular redox change
Disproportionation or auto redox change
None of the above
The correct option is B Intramolecular redox change
Explanation for the correct answer
Reactions in which one compound is broken down to simpler products by the action of heat, light, or electricity are called decomposition reactions. In these reactions, the compound absorbs the energy and when the energy is equal to the bond energy in the molecule, the bond is broken and smaller compounds are formed.
Intramolecular redox reaction occurs when one atom of a compound undergoes oxidation and another atom undergoes reduction. Potassium chlorate undergoes thermal decomposition to form potassium chloride (KCl) and oxygen gas . The balanced equation for the decomposition reaction is:
In the decomposition of potassium chlorate, the oxidation state of the oxygen atom increases from -2 to 0. Therefore, it undergoes oxidation. The oxidation state of chlorine decreases from +5 to -1 during decomposition. Therefore, chlorine undergoes reduction. The total decomposition reaction is therefore an example for intramolecular redox reaction.
Explanations for the wrong answers
(A) The decomposition reaction contains only one reactant. Therefore, an intermolecular redox reaction cannot happen during decomposition. Option (A) is incorrect.
(C) During disproportionation reaction, a single atom undergoes oxidation as well as reduction. Since different atoms undergo oxidation and reduction during the decomposition of potassium chlorate, disproportionation does not occur in decomposition. Option (C) is incorrect.
(D) Since option (B) is true, option (D) is incorrect.
Therefore, the correct answer is (B) intramolecular redox reaction. The decomposition of , to and on heating is an example of intramolecular redox change.
Intramolecular redox change
Explanation for the correct answer
Reactions in which one compound is broken down to simpler products by the action of heat, light, or electricity are called decomposition reactions. In these reactions, the compound absorbs the energy and when the energy is equal to the bond energy in the molecule, the bond is broken and smaller compounds are formed.
Intramolecular redox reaction occurs when one atom of a compound undergoes oxidation and another atom undergoes reduction. Potassium chlorate undergoes thermal decomposition to form potassium chloride (KCl) and oxygen gas . The balanced equation for the decomposition reaction is:
In the decomposition of potassium chlorate, the oxidation state of the oxygen atom increases from -2 to 0. Therefore, it undergoes oxidation. The oxidation state of chlorine decreases from +5 to -1 during decomposition. Therefore, chlorine undergoes reduction. The total decomposition reaction is therefore an example for intramolecular redox reaction.
Explanations for the wrong answers
(A) The decomposition reaction contains only one reactant. Therefore, an intermolecular redox reaction cannot happen during decomposition. Option (A) is incorrect.
(C) During disproportionation reaction, a single atom undergoes oxidation as well as reduction. Since different atoms undergo oxidation and reduction during the decomposition of potassium chlorate, disproportionation does not occur in decomposition. Option (C) is incorrect.
(D) Since option (B) is true, option (D) is incorrect.
Therefore, the correct answer is (B) intramolecular redox reaction. The decomposition of , to and on heating is an example of intramolecular redox change.
